{
  "spore": "profile",
  "id": "silvered-fep-teflon",
  "spore_version": "0.2",
  "family": "fluoropolymer-mirror",
  "name": "Silvered FEP Teflon",
  "abbreviation": "Ag/FEP",
  "role": "second-surface mirror thermal control film",
  "category": "coatings",
  "type": "optical-solar-reflectors",
  "summary": "Silvered FEP Teflon is a flexible second-surface mirror: a fluorinated ethylene propylene (FEP) film with silver and Inconel vapour-deposited on its back. Dunmore prints a typical outside-surface value of 0.13 to 0.16 for the solar absorptance and emittance pair, without splitting them, and an operating range of -185 to 125 °C. SatCatalog prints an operating range of -150 to 125 °C. In a NASA plasma-asher test, the SiOx-coated version darkened and was removed after an atomic-oxygen fluence of 1.1x10^22 atoms/cm2. Film flown on LDEF lost more than 0.001 inch of its nominal 0.005 inch thickness in its most exposed rows.\n",
  "best_for": "Flexible spacecraft thermal control where a low ratio of solar absorptance to emittance is needed, over a published range of -185 to 125 °C (Dunmore)",
  "weakest_at": "Atomic oxygen in low Earth orbit: the FEP erodes, and the SiOx barrier only protects where it has not cracked (NASA TM 106146 and NASA TM 104096)",
  "identity": {
    "formula": "Laminate of FEP film (tetrafluoroethylene and hexafluoropropylene copolymer), vapour-deposited silver and Inconel, bonded with a pressure-sensitive adhesive",
    "designations": [],
    "source": "nasa-tm104096",
    "where": "Introduction, description of the blanket material; monomers from the Wikipedia FEP article (composition only)"
  },
  "tags": {
    "environments": [
      "low-earth-orbit"
    ],
    "stresses": [
      "atomic-oxygen",
      "ultraviolet",
      "vacuum-and-outgassing"
    ],
    "applications": [
      "thermal-control"
    ]
  },
  "properties": [
    {
      "benchmark": "alpha_epsilon_outside_surface",
      "label": "Typical outside surface solar absorptance / emittance value",
      "value": 0.13,
      "value_high": 0.16,
      "bound": "range",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "product": "silvered FEP Teflon, outside surface",
        "split": "the page prints one combined pair and does not separate solar absorptance from emittance",
        "test": "not stated"
      },
      "method": "Value printed on the Dunmore product page",
      "status": "ground",
      "source": "dunmore-silver-fep",
      "where": "Product page, typical outside surface values line",
      "source_detail": {
        "title": "Dunmore, Silver FEP film product page",
        "id": "Dunmore product page, silver-fep-film",
        "url": "https://www.dunmore.com/products/silver-fep-film.html",
        "year": 2026,
        "kind": "datasheet",
        "license": "vendor web page, cited not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Operating temperature, upper limit (Dunmore)",
      "value": 125,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "silvered FEP Teflon",
        "basis": "operating temperature range as printed"
      },
      "method": "Value printed on the Dunmore product page",
      "status": "ground",
      "source": "dunmore-silver-fep",
      "where": "Product page, operating temperature line (-185 °C to 125 °C)",
      "source_detail": {
        "title": "Dunmore, Silver FEP film product page",
        "id": "Dunmore product page, silver-fep-film",
        "url": "https://www.dunmore.com/products/silver-fep-film.html",
        "year": 2026,
        "kind": "datasheet",
        "license": "vendor web page, cited not reproduced"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Operating temperature, lower limit (Dunmore)",
      "value": -185,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "silvered FEP Teflon",
        "basis": "operating temperature range as printed"
      },
      "method": "Value printed on the Dunmore product page",
      "status": "ground",
      "source": "dunmore-silver-fep",
      "where": "Product page, operating temperature line (-185 °C to 125 °C)",
      "source_detail": {
        "title": "Dunmore, Silver FEP film product page",
        "id": "Dunmore product page, silver-fep-film",
        "url": "https://www.dunmore.com/products/silver-fep-film.html",
        "year": 2026,
        "kind": "datasheet",
        "license": "vendor web page, cited not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Operating temperature, upper limit (SatCatalog)",
      "value": 125,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "silvered FEP Teflon",
        "basis": "operating temperature range as printed"
      },
      "method": "Value printed on the SatCatalog component page",
      "status": "ground",
      "source": "satcatalog-silver-teflon",
      "where": "Overview section, operating temperature range (-150 °C to 125 °C)",
      "source_detail": {
        "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
        "id": "SatCatalog component silver-teflon-fep-tape",
        "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
        "year": 2026,
        "kind": "database",
        "license": "catalog web page, cited not reproduced"
      }
    },
    {
      "benchmark": "min_service_temp",
      "label": "Operating temperature, lower limit (SatCatalog)",
      "value": -150,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "product": "silvered FEP Teflon",
        "basis": "operating temperature range as printed; differs from the Dunmore lower limit of -185 °C"
      },
      "method": "Value printed on the SatCatalog component page",
      "status": "ground",
      "source": "satcatalog-silver-teflon",
      "where": "Overview section, operating temperature range (-150 °C to 125 °C)",
      "source_detail": {
        "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
        "id": "SatCatalog component silver-teflon-fep-tape",
        "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
        "year": 2026,
        "kind": "database",
        "license": "catalog web page, cited not reproduced"
      }
    },
    {
      "benchmark": "reflectance",
      "label": "Reflectance",
      "value": 90,
      "bound": "lower",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "printed as Reflectance >90%; wavelength and reflectance type not stated"
      },
      "method": "Value printed on the SatCatalog component page",
      "status": "ground",
      "source": "satcatalog-silver-teflon",
      "where": "Overview section, Optical Performance",
      "source_detail": {
        "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
        "id": "SatCatalog component silver-teflon-fep-tape",
        "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
        "year": 2026,
        "kind": "database",
        "license": "catalog web page, cited not reproduced"
      }
    },
    {
      "benchmark": "normal_emittance",
      "label": "Normal emittance",
      "value": 40,
      "value_high": 80,
      "bound": "range",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "basis": "printed as 40-80% depending on film thickness; the page does not pair each value with a thickness"
      },
      "method": "Value printed on the SatCatalog component page",
      "status": "ground",
      "source": "satcatalog-silver-teflon",
      "where": "Overview section, Optical Performance",
      "source_detail": {
        "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
        "id": "SatCatalog component silver-teflon-fep-tape",
        "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
        "year": 2026,
        "kind": "database",
        "license": "catalog web page, cited not reproduced"
      }
    },
    {
      "benchmark": "film_thickness",
      "label": "Film thickness range",
      "value": 50,
      "value_high": 250,
      "bound": "range",
      "unit": "μm",
      "scope": "material",
      "conditions": {
        "product": "silvered FEP Teflon film",
        "basis": "range as printed; not a single thickness"
      },
      "method": "Value printed on the Dunmore product page",
      "status": "ground",
      "source": "dunmore-silver-fep",
      "where": "Product page, film thickness line",
      "source_detail": {
        "title": "Dunmore, Silver FEP film product page",
        "id": "Dunmore product page, silver-fep-film",
        "url": "https://www.dunmore.com/products/silver-fep-film.html",
        "year": 2026,
        "kind": "datasheet",
        "license": "vendor web page, cited not reproduced"
      }
    },
    {
      "benchmark": "maximum_film_width",
      "label": "Maximum film width",
      "value": 24,
      "bound": "exact",
      "unit": "inches",
      "scope": "material",
      "conditions": {
        "basis": "printed as maximum film width under Customization"
      },
      "method": "Value printed on the SatCatalog component page",
      "status": "ground",
      "source": "satcatalog-silver-teflon",
      "where": "Overview section, Customization",
      "source_detail": {
        "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
        "id": "SatCatalog component silver-teflon-fep-tape",
        "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
        "year": 2026,
        "kind": "database",
        "license": "catalog web page, cited not reproduced"
      }
    },
    {
      "benchmark": "silver_layer_thickness",
      "label": "Vapour-deposited silver layer",
      "value": 1600,
      "bound": "exact",
      "unit": "Å",
      "scope": "material",
      "conditions": {
        "basis": "nominal, as printed for the LDEF blanket material",
        "layer": "silver on the back of the FEP film"
      },
      "method": "Value printed in the NASA description of the blanket",
      "status": "ground",
      "source": "nasa-tm104096",
      "where": "Introduction, description of the blanket (approximately 1600A of vapor deposited silver)",
      "source_detail": {
        "title": "An Analysis of LDEF-Exposed Silvered FEP Teflon Thermal Blanket Material (NASA TM 104096)",
        "id": "NASA TM 104096; NTRS 19920005971",
        "url": "https://ntrs.nasa.gov/api/citations/19920005971/downloads/19920005971.pdf",
        "year": 1992,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "inconel_layer_thickness",
      "label": "Vapour-deposited Inconel layer",
      "value": 400,
      "bound": "exact",
      "unit": "Å",
      "scope": "material",
      "conditions": {
        "basis": "nominal, as printed for the LDEF blanket material",
        "layer": "Inconel over the silver"
      },
      "method": "Value printed in the NASA description of the blanket",
      "status": "ground",
      "source": "nasa-tm104096",
      "where": "Introduction, description of the blanket (approximately 400A of vapor deposited inconel)",
      "source_detail": {
        "title": "An Analysis of LDEF-Exposed Silvered FEP Teflon Thermal Blanket Material (NASA TM 104096)",
        "id": "NASA TM 104096; NTRS 19920005971",
        "url": "https://ntrs.nasa.gov/api/citations/19920005971/downloads/19920005971.pdf",
        "year": 1992,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "ao_erosion_depth",
      "label": "FEP film loss in LDEF Rows 8 to 10",
      "value": 0.001,
      "bound": "lower",
      "unit": "inch",
      "scope": "material",
      "conditions": {
        "exposure": "5 years 9 months in low Earth orbit on LDEF, most extreme rows 8 to 10",
        "starting_thickness": "0.005 inch nominal FEP film",
        "note": "printed as in excess of 0.001 inch"
      },
      "method": "Preliminary estimate by the authors",
      "status": "ground",
      "source": "nasa-tm104096",
      "where": "Discussion of LDEF film erosion, paragraph beginning Preliminary estimates",
      "source_detail": {
        "title": "An Analysis of LDEF-Exposed Silvered FEP Teflon Thermal Blanket Material (NASA TM 104096)",
        "id": "NASA TM 104096; NTRS 19920005971",
        "url": "https://ntrs.nasa.gov/api/citations/19920005971/downloads/19920005971.pdf",
        "year": 1992,
        "kind": "report",
        "license": "public domain (NASA)"
      }
    },
    {
      "benchmark": "melting_point",
      "label": "Melt point of the bare FEP film",
      "value": 260,
      "value_high": 280,
      "bound": "range",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film, 1 mil (0.025 mm) basis, not the silvered blanket",
        "test": "ASTM D3418 (DTA)"
      },
      "method": "Value printed in the Typical Properties table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Typical Properties table, Thermal section, Melt Point (printed 260–280 °C)",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "zero_strength_temperature",
      "label": "Zero strength temperature of the bare FEP film",
      "value": 255,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film, 1 mil basis",
        "load": "temperature at which a film supports 0.14 N/mm2 (20 psi) for 5 sec, per the bulletin footnote"
      },
      "method": "Value printed in the Typical Properties table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Typical Properties table, Thermal section, Zero Strength Temperature",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "max_service_temp",
      "label": "Continuous service temperature, upper limit (bare FEP film)",
      "value": 205,
      "bound": "exact",
      "unit": "°C",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film resin, not the silvered blanket",
        "basis": "continuous service range as printed"
      },
      "method": "Value printed in the bulletin description bullets",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Description bullets, continuous service temperature (–240 to 205 °C)",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "density",
      "label": "Density of the bare FEP film",
      "value": 2150,
      "bound": "exact",
      "unit": "kg/m3",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film, 1 mil basis",
        "test": "ASTM D1505"
      },
      "method": "Value printed in the Miscellaneous table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Miscellaneous table, Density",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "ultimate_tensile_strength",
      "label": "Tensile strength at break of the bare FEP film",
      "value": 21,
      "bound": "exact",
      "unit": "N/mm2",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film, 1 mil (0.025 mm) basis at 25 °C",
        "test": "ASTM D882"
      },
      "method": "Value printed in the Mechanical table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Mechanical table, Tensile Strength at Break (3000 psi)",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "elongation",
      "label": "Elongation at break of the bare FEP film",
      "value": 300,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film, 1 mil (0.025 mm) basis at 25 °C",
        "test": "ASTM D882"
      },
      "method": "Value printed in the Mechanical table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Mechanical table, Elongation at Break",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "dielectric_constant",
      "label": "Dielectric constant of the bare FEP film",
      "value": 2,
      "bound": "exact",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film at 25 °C",
        "frequency": "100 Hz to 1 MHz",
        "test": "ASTM D150"
      },
      "method": "Value printed in the Electrical table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Electrical table, Dielectric Constant",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "refractive_index",
      "label": "Refractive index of the bare FEP film",
      "value": 1.341,
      "value_high": 1.347,
      "bound": "range",
      "unit": "-",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film",
        "test": "ASTM D542"
      },
      "method": "Value printed in the Miscellaneous table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Miscellaneous table, Refractive Index",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "solar_transmittance",
      "label": "Solar transmission of the bare FEP film",
      "value": 96,
      "bound": "exact",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film, 1 mil (0.025 mm) basis at 25 °C",
        "test": "ASTM E-424",
        "note": "the silvered blanket is opaque to solar transmission because of its silver layer"
      },
      "method": "Value printed in the Miscellaneous table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Miscellaneous table, Solar Transmission",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "specific_heat",
      "label": "Specific heat of the bare FEP film",
      "value": 1172,
      "bound": "exact",
      "unit": "J/(kg·K)",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film"
      },
      "method": "Value printed in the Thermal table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Thermal table, Specific Heat (0.28 Btu/(lb·°F))",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "thermal_conductivity",
      "label": "Thermal conductivity of the bare FEP film",
      "value": 0.195,
      "bound": "exact",
      "unit": "W/(m·K)",
      "scope": "material",
      "conditions": {
        "form": "bare Teflon FEP film",
        "method_printed": "Cenco-Fitch"
      },
      "method": "Value printed in the Thermal table",
      "status": "ground",
      "source": "chemours-fep-bulletin",
      "where": "Thermal table, Coefficient of Thermal Conductivity",
      "source_detail": {
        "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
        "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
        "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
        "year": 2022,
        "kind": "datasheet",
        "license": "manufacturer bulletin, cited not reproduced"
      }
    },
    {
      "benchmark": "total_mass_loss",
      "label": "Total mass loss limit (ASTM E-595)",
      "value": 1,
      "bound": "upper",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "standard": "ASTM E-595",
        "kind": "qualification limit printed by the vendor, not a measured result for this product"
      },
      "method": "Limit printed on the SatCatalog component page (printed as TML <1.0%)",
      "status": "ground",
      "source": "satcatalog-silver-teflon",
      "where": "Qualification and Testing section",
      "source_detail": {
        "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
        "id": "SatCatalog component silver-teflon-fep-tape",
        "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
        "year": 2026,
        "kind": "database",
        "license": "catalog web page, cited not reproduced"
      }
    },
    {
      "benchmark": "collected_volatile_condensable_material",
      "label": "Collected volatile condensable material limit (ASTM E-595)",
      "value": 0.1,
      "bound": "upper",
      "unit": "%",
      "scope": "material",
      "conditions": {
        "standard": "ASTM E-595",
        "kind": "qualification limit printed by the vendor, not a measured result for this product"
      },
      "method": "Limit printed on the SatCatalog component page (printed as CVCM <0.1%)",
      "status": "ground",
      "source": "satcatalog-silver-teflon",
      "where": "Qualification and Testing section",
      "source_detail": {
        "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
        "id": "SatCatalog component silver-teflon-fep-tape",
        "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
        "year": 2026,
        "kind": "database",
        "license": "catalog web page, cited not reproduced"
      }
    }
  ],
  "corrosion": [
    {
      "environment": "Atomic oxygen in low Earth orbit, simulated in an RF plasma asher",
      "headline": "In NASA's plasma-asher test the SiOx/FEP/Ag sample darkened and was removed at 1.1x10^22 atoms/cm2.",
      "effect": "At that fluence the sample's solar absorptance rose and its thermal emittance fell sharply. The sample turned into a black, tar-like film that began at its unprotected edges, where the silver and silicone adhesive oxidised. NASA states that atomic oxygen oxidises FEP, causing mass loss and surface texturing, and that the asher gives a random-direction attack, unlike the directed beam in orbit.",
      "rating": "severe",
      "conditions": {
        "facility": "RF oxygen plasma asher with intense VUV",
        "fluence": "1.1x10 22 atoms/cm2 at removal",
        "caveat": "the test is not a direct lifetime prediction, because the asher attack is random"
      },
      "source": "nasa-tm106146",
      "where": "Damage Mechanisms to Coatings; Exposure in an RF Plasma Asher; RF Plasma Asher Effects on Coatings"
    },
    {
      "environment": "Low Earth orbit in flight, LDEF, 5 years 9 months",
      "headline": "Silvered FEP on LDEF lost more than 0.001 inch of its 0.005 inch film in the most exposed rows.",
      "effect": "Atomic-oxygen erosion roughened the coating surface, and some pieces changed from specular to diffuse reflectors. XPS, infrared and thermal analysis found no significant change at the molecular level. The authors call the erosion extent unanticipated, and note that it was not uniform across the film.",
      "rating": "severe",
      "conditions": {
        "exposure": "5 years 9 months on LDEF, Rows 8 to 10 (most extreme cases)",
        "note": "the film-loss figure is a preliminary estimate"
      },
      "source": "nasa-tm104096",
      "where": "Abstract; Discussion of LDEF film erosion"
    },
    {
      "environment": "Ultraviolet and vacuum-ultraviolet radiation in orbit",
      "headline": "NASA's review says UV can embrittle FEP, degrade transmittance and cause mass loss over long exposure.",
      "effect": "The review states that ultraviolet radiation may cause embrittlement, transmittance degradation and mass loss over a long exposure duration. It notes that atomic oxygen and UV act together on FEP, and that a SiOx coating does not stop UV that reaches the FEP through cracks.",
      "rating": "moderate",
      "conditions": {
        "basis": "statement in the NASA review; no UV dose or number is printed for this laminate"
      },
      "source": "nasa-tm106146",
      "where": "Damage Mechanisms to Coatings, paragraph on SiOx/FEP/Ag"
    },
    {
      "environment": "Thermal cycling and micrometeoroid or debris impact",
      "headline": "Cracks from thermal cycling let atomic oxygen reach the FEP, and impacts can delaminate the film.",
      "effect": "NASA notes that cracks in the SiOx coating caused by thermal cycling let atomic oxygen and UV reach the FEP, changing its optical properties. LDEF showed delamination of FEP from the silver around impact sites, and exposed silicone adhesive at an impact site can form a dark contaminant with atomic oxygen and UV.",
      "rating": "moderate",
      "conditions": {
        "thermal_cycling_in_test": "10 cycles between -93 °C and +49 °C in vacuum, before plasma-asher exposure"
      },
      "source": "nasa-tm106146",
      "where": "Damage Mechanisms to Coatings; Vacuum Thermal Cycling Exposure"
    },
    {
      "environment": "Outgassing in vacuum",
      "headline": "The SatCatalog page quotes ASTM E-595 limits of TML below 1.0% and CVCM below 0.1%.",
      "effect": "These are qualification limits printed by the vendor catalog, not measured results for this product. The page does not give the test lot, date or specimen.",
      "rating": "low",
      "conditions": {
        "standard": "ASTM E-595",
        "basis": "limits as printed on the SatCatalog page"
      },
      "source": "satcatalog-silver-teflon",
      "where": "Qualification and Testing section"
    }
  ],
  "risks": {
    "hazards": [
      {
        "text": "The bulk silver safety data sheet (Stanford Advanced Materials, product Silver, brand SAM, revision 09/04/2017) classifies silver as acute aquatic toxicity Category 1 (H400) and chronic aquatic toxicity Category 1 (H410), with signal word Warning and precautionary statement P273, avoid release to the environment.",
        "ghs": [
          "H400",
          "H410"
        ],
        "source": "sds-silver-sam",
        "where": "Sections 2.1 and 2.2"
      },
      {
        "text": "The same sheet prints an oral LD50 for silver in rat of more than 5,000 mg/kg (male), and 'No data available' for inhalation and dermal toxicity.",
        "ghs": [],
        "source": "sds-silver-sam",
        "where": "Section 11.1"
      },
      {
        "text": "The same sheet prints silver exposure limits of TWA 0.01 mg/m3 (OSHA Table Z-1) and TWA 0.1 mg/m3 (ACGIH TLV).",
        "ghs": [],
        "source": "sds-silver-sam",
        "where": "Section 8.1, control parameters"
      },
      {
        "text": "The Chemours FEP bulletin says the polymer is chemically inert and solvent resistant to virtually all chemicals, except molten alkali metals, gaseous fluorine and certain complex halogenated compounds at elevated temperatures and pressures.",
        "ghs": [],
        "source": "chemours-fep-bulletin",
        "where": "Chemical compatibility paragraph"
      }
    ],
    "failure_risks": [
      {
        "mode": "Atomic-oxygen attack through cracks in the SiOx barrier",
        "trigger": "Cracks from thermal cycling in the SiOx coating, exposing the FEP",
        "consequence": "Atomic oxygen and UV reach the FEP, changing its optical properties and the integrity of the coating (NASA TM 106146)",
        "severity": "high",
        "source": "nasa-tm106146",
        "where": "Damage Mechanisms to Coatings"
      },
      {
        "mode": "Darkening and oxidation of unprotected edges",
        "trigger": "Plasma-asher exposure to 1.1x10^22 atoms/cm2, with unprotected sample edges",
        "consequence": "Solar absorptance rose and emittance fell sharply, and the silver and silicone adhesive oxidised into a black, tar-like film (NASA TM 106146)",
        "severity": "high",
        "source": "nasa-tm106146",
        "where": "RF Plasma Asher Effects on Coatings"
      },
      {
        "mode": "Delamination around micrometeoroid or debris impacts",
        "trigger": "Impacts in orbit",
        "consequence": "FEP delaminated from the silver around impact sites on LDEF, and exposed silicone adhesive can form a dark deposit (NASA TM 106146)",
        "severity": "moderate",
        "source": "nasa-tm106146",
        "where": "Damage Mechanisms to Coatings"
      },
      {
        "mode": "Erosion and roughening of the FEP surface",
        "trigger": "Long exposure in low Earth orbit (LDEF, 5 years 9 months)",
        "consequence": "Film lost more than 0.001 inch of 0.005 inch in the most exposed rows, and some pieces changed from specular to diffuse reflectors (NASA TM 104096)",
        "severity": "high",
        "source": "nasa-tm104096",
        "where": "Abstract; Discussion of LDEF film erosion"
      }
    ],
    "side_effects": [
      {
        "text": "Atomic oxygen and UV acting together with silicones can produce a dark-coloured contaminant deposit on nearby surfaces (NASA TM 106146).",
        "affects": "Nearby spacecraft surfaces",
        "source": "nasa-tm106146",
        "where": "Damage Mechanisms to Coatings"
      }
    ],
    "handling": [
      {
        "text": "Bulk silver: air sensitive; store under inert gas and keep in a dry place (safety data sheet, storage section). This applies to the silver metal, not to the finished film.",
        "source": "sds-silver-sam",
        "where": "Section 7"
      },
      {
        "text": "Teflon FEP film is rated VTM-0 under ANSI/UL 94 with an oxygen index of 95% (ASTM D2863), per the bulletin, for the bare film at 1 mil.",
        "source": "chemours-fep-bulletin",
        "where": "Mechanical and Flammability rows of the Typical Properties table"
      }
    ],
    "mitigations": [
      {
        "text": "A SiOx barrier coat reduces atomic-oxygen attack on the FEP, but thermal-cycling cracks leave gaps in it (NASA TM 106146).",
        "source": "nasa-tm106146",
        "where": "Damage Mechanisms to Coatings"
      }
    ]
  },
  "uses": [
    {
      "application": "thermal-control",
      "device": "Thermal control blanket on Space Station Freedom power-system radiators (candidate coating in NASA's test, not a flown product in this source)",
      "example": "NASA tested SiOx-coated silvered Teflon with white paints and anodised aluminium as candidate radiator coatings for Space Station Freedom, against a 30-year design life.",
      "source": "nasa-tm106146",
      "where": "Introduction; Materials Tested"
    },
    {
      "application": "thermal-control",
      "device": "Thermal blanket on LDEF experiment trays",
      "example": "Silvered FEP thermal blankets provided thermal protection for experiments on LDEF Tray F2 and Trays C5, C8 and A10.",
      "source": "nasa-tm104096",
      "where": "Section 1, Introduction"
    },
    {
      "application": "thermal-control",
      "device": "Flexible second-surface mirror in spacecraft thermal control",
      "example": "NASA describes the blanket material, also known as flexible second-surface mirror thermal control coating, as used in a variety of space applications where thermal protection is a consideration.",
      "source": "nasa-tm104096",
      "where": "Section 1, Introduction"
    }
  ],
  "supply": [
    {
      "subject": "Silver",
      "producers": [
        {
          "country": "Mexico",
          "share_percent": 24.2,
          "year": 2025
        },
        {
          "country": "Peru",
          "share_percent": 13.8,
          "year": 2025
        },
        {
          "country": "China",
          "share_percent": 13.1,
          "year": 2025
        },
        {
          "country": "Bolivia",
          "share_percent": 5.8,
          "year": 2025
        },
        {
          "country": "Chile",
          "share_percent": 5.4,
          "year": 2025
        }
      ],
      "critical_lists": [
        {
          "list": "USGS 2025 Final List of Critical Minerals (silver added)",
          "listed": true
        },
        {
          "list": "EU critical raw materials list",
          "listed": false
        }
      ],
      "recycling": "USGS: about 1,000 tons of silver was recovered from new and old scrap in 2025, about 11% of apparent consumption.",
      "substitutes": [],
      "source": "usgs-mcs2026-silver",
      "where": "World Mine Production and Reserves table, 2025e (world total rounded 26,000 t). Shares calculated by Space Mushroom as printed tons divided by the rounded world total. Critical list change in the opening paragraph. Recycling paragraph."
    }
  ],
  "media": [],
  "documents": [
    {
      "title": "Dunmore: Silver FEP film product page",
      "type": "datasheet",
      "url": "https://www.dunmore.com/products/silver-fep-film.html",
      "year": 2026
    },
    {
      "title": "SatCatalog: Silver Teflon FEP tape component page",
      "type": "database",
      "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
      "year": 2026
    },
    {
      "title": "NASA TM 106146: The Effects of Simulated Low Earth Orbit Environments on Spacecraft Thermal Control Coatings (Dever et al., 1993)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/19930017830/downloads/19930017830.pdf",
      "year": 1993
    },
    {
      "title": "NASA TM 104096: An Analysis of LDEF-Exposed Silvered FEP Teflon Thermal Blanket Material (Young and Slemp, 1992)",
      "type": "report",
      "url": "https://ntrs.nasa.gov/api/citations/19920005971/downloads/19920005971.pdf",
      "year": 1992
    },
    {
      "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (copy hosted by PolymerFilms)",
      "type": "datasheet",
      "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
      "year": 2022
    },
    {
      "title": "USGS Mineral Commodity Summaries 2026: Silver",
      "type": "report",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silver.pdf",
      "year": 2026
    },
    {
      "title": "Safety Data Sheet: Silver (Stanford Advanced Materials, brand SAM, version 3.0)",
      "type": "sds",
      "url": "https://www.sputtertargets.net/wp-content/uploads/2018/05/Silver-Ag-sds.pdf",
      "year": 2017
    }
  ],
  "gaps": [
    "No flight-heritage details are verified: SatCatalog prints Heritage Yes without listing missions. The brief's Hubble and ISS use is not confirmed by any page read in this run, so it is not in uses.",
    "Solar absorptance (alpha) and infrared emittance (epsilon) are not given separately. Dunmore prints one combined pair (0.13 to 0.16), and SatCatalog prints normal emittance of 40-80% by thickness without alpha.",
    "The two operating ranges disagree on the lower limit (Dunmore -185 °C, SatCatalog -150 °C). Both are kept, each with its source. Neither is tied to a test standard.",
    "The Dunmore page names an Inconel protective layer over the silver but does not print a SiOx layer, its thickness, the FEP thickness on the product, or the adhesive. SiOx and the Permacel P223 adhesive come from the NASA test samples only.",
    "No atomic-oxygen erosion yield or solar absorptance and emittance change values for this material were read as numbers. NASA's test results are shown in figures only, so no value was taken from them.",
    "The Wikipedia article says FEP contains about 5% of the 'propylene component'. The term is ambiguous, so the share was not used.",
    "The FEP film's own thermal decomposition products and hazard statements were not found. PubChem's silver record was blocked by a reCAPTCHA and could not be read.",
    "The silver safety data sheet is for bulk silver metal (brand SAM, revision 09/04/2017). The silvered film has no safety data sheet read in this run.",
    "Silver abundance in the Earth's crust was not found in a page read in this run.",
    "No supply data for FEP resin producers or feedstock was read. The supply section covers silver only.",
    "The EU critical raw materials list status for silver was not checked.",
    "No substitute for silvered FEP in thermal control was found in a page read in this run.",
    "No standard grade designations apply to this coating. The bulletin's 'Teflon FEP' trade name is not listed as a designation.",
    "No image with a confirmed licence was fetched, so media is not included.",
    "Thermal-cycling and UV effects are described in NASA's text, but no numeric change for this laminate was read from the text.",
    "The ASTM E-595 limits are quoted from SatCatalog and were not checked against the ASTM standard."
  ],
  "story": {
    "why": "Silvered FEP Teflon is a flexible second-surface mirror. The silver sits behind a transparent fluoropolymer film, so the film faces space and the reflective metal is protected from the outside. The construction is used where a low solar absorptance and a high infrared emittance are both needed in a thin, bendable sheet. Vendor pages give a combined value of 0.13 to 0.16 for the outside surface, and NASA reports that the SiOx-coated version is damaged by atomic oxygen in low Earth orbit.",
    "uses": [
      {
        "where": "Space Station Freedom radiators (candidate)",
        "line": "NASA tested SiOx-coated silvered Teflon as a candidate coating for Space Station Freedom power-system radiators, along with two white paints and anodised aluminium. The test asked for a 30-year design life."
      },
      {
        "where": "LDEF experiment trays",
        "line": "NASA's analysis of LDEF material describes silvered FEP blankets that gave thermal protection to experiments on Tray F2 and Trays C5, C8 and A10 on the Long Duration Exposure Facility."
      },
      {
        "where": "Spacecraft thermal blankets",
        "line": "NASA describes the material as a flexible second-surface mirror thermal control coating used in a variety of space applications where thermal protection is a consideration."
      }
    ],
    "can_do": [
      {
        "label": "Low solar absorptance to emittance",
        "line": "Dunmore prints a typical outside-surface value of 0.13 to 0.16 for the solar absorptance and emittance pair. The page does not split the two values, so this profile does not state either one alone.",
        "scope": "material",
        "value": "0.13 to 0.16 outside surface"
      },
      {
        "label": "Operating temperature",
        "line": "Dunmore prints an operating range of -185 to 125 °C. SatCatalog prints -150 to 125 °C. Both are kept because the vendors do not agree on the lower limit.",
        "scope": "material",
        "value": "-185 to 125 °C (Dunmore)"
      },
      {
        "label": "Atomic-oxygen erosion",
        "line": "On LDEF, the most exposed film lost more than 0.001 inch of its 0.005 inch thickness in 5 years and 9 months, according to NASA's preliminary estimate.",
        "scope": "material",
        "value": "more than 0.001 inch lost"
      },
      {
        "label": "Outgassing limits",
        "line": "SatCatalog quotes ASTM E-595 limits of TML below 1.0% and CVCM below 0.1%. These are qualification limits, not measured results for this product.",
        "scope": "material",
        "value": "TML below 1.0%, CVCM below 0.1%"
      }
    ],
    "compare": "Silvered FEP trades atomic-oxygen tolerance for a low solar absorptance. In NASA's 1993 plasma-asher test, the SiOx/FEP/Ag sample was removed at 1.1x10^22 atoms/cm2 after severe degradation, while the white paints Z-93 and YB-71 and the anodised aluminium were carried through the full test fluence in the same asher test (the full value is printed in NASA TM 106146, Exposure in an RF Plasma Asher). The bare FEP film is rated for a continuous service range of -240 to 205 °C, but the silvered product's own published range is -185 to 125 °C (Dunmore) or -150 to 125 °C (SatCatalog).",
    "compare_rows": [
      {
        "label": "Operating range, upper limit",
        "benchmark": "max_service_temp",
        "scope": "material"
      },
      {
        "label": "Melt point of the bare FEP film",
        "benchmark": "melting_point",
        "scope": "material"
      },
      {
        "label": "Density of the bare FEP film",
        "benchmark": "density",
        "scope": "material"
      }
    ],
    "handling": [
      "The bulk silver metal is classed as very toxic to aquatic life. Avoid releasing it to the environment.",
      "Keep the silver metal under inert gas and dry. This does not describe the finished film.",
      "The film is rated VTM-0 under UL 94 for the bare FEP at 1 mil."
    ],
    "good_for": [
      "Thin, flexible thermal control on spacecraft, where a low solar absorptance and a high emittance are both needed (Dunmore and NASA).",
      "Use over a published operating range of -185 to 125 °C, according to Dunmore."
    ],
    "watch_out": [
      "Atomic oxygen in low Earth orbit erodes the FEP. On LDEF, the most exposed film lost more than 0.001 inch.",
      "A SiOx barrier does not protect the FEP where thermal cycling has cracked it, according to NASA.",
      "The two published operating ranges disagree on the lower limit: -185 °C (Dunmore) and -150 °C (SatCatalog)."
    ],
    "verdict": "Silvered FEP is a well-documented thermal-control film for the sunward side of a spacecraft. Its low solar absorptance is useful, but its atomic-oxygen tolerance depends on the barrier staying intact, and the published data do not settle the lower operating limit.",
    "recipe": {
      "line": "Silvered FEP is a laminate: a nominally 5 mil fluorinated ethylene propylene film with about 1600 Å of silver and about 400 Å of Inconel vapour-deposited on its back (NASA TM 104096). Silver reflects sunlight, the transparent film protects it, and a SiOx barrier coat sits on the FEP side in the test construction NASA called SiOx/FEP/Ag (NASA TM 106146).",
      "parts": [
        {
          "name": "Fluorinated ethylene propylene (FEP) film",
          "role": "Transparent outer layer. Sunlight passes through it and is reflected by the silver, which gives a low solar absorptance."
        },
        {
          "name": "Silver",
          "symbol": "Ag",
          "role": "Specular reflector behind the film."
        },
        {
          "name": "Inconel",
          "role": "Thin metal layer over the silver. Dunmore calls it a protective layer."
        },
        {
          "name": "Silicon oxide (SiOx) barrier",
          "role": "Barrier to atomic oxygen on the FEP in the NASA test construction. Its thickness and whether vendor product uses it are not confirmed."
        },
        {
          "name": "Pressure-sensitive adhesive",
          "role": "Bonds the laminate to the substrate. The adhesive on the vendor product is not stated."
        }
      ]
    },
    "risk_groups": [
      {
        "title": "For people",
        "lead": "The finished film has no safety data sheet read in this run. The bulk silver safety data sheet classifies silver as very toxic to aquatic life with long-lasting effects.",
        "points": [
          {
            "label": "The silver metal",
            "line": "The bulk silver sheet classifies silver as H400 and H410 (very toxic to aquatic life) and prints an oral LD50 in rat of more than 5,000 mg/kg. It prints an OSHA limit of 0.01 mg/m3 and an ACGIH limit of 0.1 mg/m3."
          },
          {
            "label": "The FEP film",
            "line": "The Chemours bulletin describes the polymer as chemically inert to virtually all chemicals. No hazard statement for the film was found in a page read in this run."
          }
        ],
        "level": 0,
        "verdict": "Low hazard as a finished film; the bulk silver safety data…"
      },
      {
        "title": "If the film is damaged in orbit",
        "lead": "These results come from ground tests and one flight sample, not from incidents.",
        "points": [
          {
            "label": "Atomic oxygen",
            "line": "In NASA's plasma-asher test, the SiOx/FEP/Ag sample was removed at 1.1x10^22 atoms/cm2 after severe darkening. On LDEF, the most exposed film lost more than 0.001 inch of 0.005 inch."
          },
          {
            "label": "Impacts",
            "line": "NASA reports that FEP delaminated from the silver around impact sites on LDEF, and that exposed silicone adhesive can form a dark deposit on nearby surfaces."
          }
        ]
      },
      {
        "title": "Handling and storage",
        "points": [
          {
            "label": "Storage of the silver metal",
            "line": "The bulk silver sheet says the metal is air sensitive, so it should be stored under inert gas and kept dry. This does not describe the finished film."
          },
          {
            "label": "Flammability of the film",
            "line": "The bulletin rates the bare FEP film VTM-0 under UL 94, with an oxygen index of 95%."
          }
        ]
      }
    ]
  },
  "updated": "2026-11-01",
  "review": {
    "status": "draft",
    "method": "assistant",
    "checked_values": 25,
    "unreachable": 1,
    "caveats": 3,
    "note": "Written by an AI assistant on 2026-11-01 from pages read in this run. PubChem was blocked by a reCAPTCHA. Values are copied as printed; the Dunmore pair is not split into alpha and epsilon."
  },
  "sources": {
    "dunmore-silver-fep": {
      "title": "Dunmore, Silver FEP film product page",
      "id": "Dunmore product page, silver-fep-film",
      "url": "https://www.dunmore.com/products/silver-fep-film.html",
      "year": 2026,
      "kind": "datasheet",
      "license": "vendor web page, cited not reproduced"
    },
    "satcatalog-silver-teflon": {
      "title": "SatCatalog, Silver Teflon FEP tape component page (vendor SQUID3 Space)",
      "id": "SatCatalog component silver-teflon-fep-tape",
      "url": "https://www.satcatalog.com/component/silver-teflon-fep-tape",
      "year": 2026,
      "kind": "database",
      "license": "catalog web page, cited not reproduced"
    },
    "nasa-tm106146": {
      "title": "The Effects of Simulated Low Earth Orbit Environments on Spacecraft Thermal Control Coatings (NASA TM 106146, SAMPE 1993)",
      "id": "NASA TM 106146; NTRS 19930017830",
      "url": "https://ntrs.nasa.gov/api/citations/19930017830/downloads/19930017830.pdf",
      "year": 1993,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "nasa-tm104096": {
      "title": "An Analysis of LDEF-Exposed Silvered FEP Teflon Thermal Blanket Material (NASA TM 104096)",
      "id": "NASA TM 104096; NTRS 19920005971",
      "url": "https://ntrs.nasa.gov/api/citations/19920005971/downloads/19920005971.pdf",
      "year": 1992,
      "kind": "report",
      "license": "public domain (NASA)"
    },
    "chemours-fep-bulletin": {
      "title": "Teflon FEP Fluoropolymer Film Properties Bulletin (Chemours name; copy hosted by PolymerFilms, footer names Polymershapes)",
      "id": "Teflon FEP film bulletin, 1 mil basis for typical values",
      "url": "https://polymerfilms.com/wp-content/uploads/2023/06/Chemours-Teflon_FEP-Datasheet-cobranded-pf.pdf",
      "year": 2022,
      "kind": "datasheet",
      "license": "manufacturer bulletin, cited not reproduced"
    },
    "usgs-mcs2026-silver": {
      "title": "Mineral Commodity Summaries 2026, Silver",
      "id": "USGS MCS 2026",
      "url": "https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-silver.pdf",
      "year": 2026,
      "kind": "report",
      "license": "public domain (USGS)"
    },
    "sds-silver-sam": {
      "title": "Safety Data Sheet: Silver (Stanford Advanced Materials, brand SAM, version 3.0, revision 09/04/2017)",
      "id": "CAS 7440-22-4; revision 09/04/2017",
      "url": "https://www.sputtertargets.net/wp-content/uploads/2018/05/Silver-Ag-sds.pdf",
      "year": 2017,
      "kind": "datasheet",
      "license": "supplier document, linked not reproduced"
    },
    "wikipedia-fep": {
      "title": "Fluorinated ethylene propylene (Wikipedia), used for monomers and composition only",
      "id": "Wikipedia article, Fluorinated ethylene propylene",
      "url": "https://en.wikipedia.org/wiki/Fluorinated_ethylene_propylene",
      "year": 2026,
      "kind": "web",
      "license": "CC BY-SA 4.0 (Wikipedia)"
    }
  },
  "license": "CC-BY-4.0",
  "url": "https://spacemushroom.com/profiles/silvered-fep-teflon/"
}